1. Field of the Invention
This invention relates to an infrared head set.
2. Description of the Prior Art
DE-33 25 031 C2 discloses an infrared head set which consists of two reproducing converters which are connected to one another via a chin bow, of an electrical circuit which picks up the infrared signals and converts them into audio signals, and of two microphones with downstream microphone amplifiers. The circuit of this infrared head set is made such that the signals tapped from the infrared circuit or the microphone amplifiers are selectively supplied individually or in combination to the reproducing converters. In doing so the microphones are arranged at a distance from one another on the chin bow such that they are located symmetrically to the medial plane of the head of the user, the signals tapped from the microphones being supplied opposite in phase in the same ratio to the microphone amplifier.
This infrared head set is conventionally dynamically connected to a transmitter which converts the emitted audio signals, for example from a television set or a HiFi system, into invisible infrared rays and emits them into space, where they are received by the infrared head set, with which wireless infrared audio transmission can be made available. Feasibly this transmitter is at the same time the charging station for the infrared receiver and for at least one battery insert which is used in the charged state for operation of the infrared head set.
Publication WO 95/35011 A discloses an infrared head set made as a chin bow receiver. This infrared head set consists essentially of a base housing, and of two bow ends with one miniature speaker located on the each end. The two ends of the bow are supported in the base housing, and they can be spread each in conjunction with a spring element which acts in the area of the support, with which via these spring elements comfortable ear insertion of the miniature speakers can be effected. Turning on and off in this headset is done by means of a hand-operated switch.
Publications GB 2 304 488 A and FR 2 280 283 A likewise disclose cable-free head sets in which the spreadable head bows likewise enable comfortable ear insertion, and into which an on/off switch is integrated, with on-and off-actuation which depends on the spread of the bow, with which manual actuation of the switch becomes superfluous.
The invention is an infrared head set with increased ease of operation, acceptance and the availability of one such device.
In an infrared head set which is also called a chin bow receiver, audio signals are received via invisible infrared radiation carrier which are amplified in the chin bow receiver via the miniature speakers which are attached to the two ends of the bow. The audio signals are relayed to the ears.
With the invention the ends of the bow are connected to the base housing, which on the end side are each equipped with one miniature speaker, and which form together a chin bow receiver, that are elastically spreadable in at least one plane by a supported guide. Thus, on the one hand comfortable ear-side insertion of the miniature speakers is achieved, on the other hand this controlled spreading leads to the chin bow receiver being automatically turned on by the spreading being dynamically connected to a switch which is placed preferably in the base housing. Furthermore, by this arrangement the wearing of the chin bow receiver dynamically connected to the arrangement of the miniature speakers is made comfortable by preventing uncomfortable pressure points on the parts of the ear being formed. When the chin bow receiver is laid down, it is automatically switched off. For the wearer this means that insertion takes place by grasping the two miniature speakers on the two ends of the bow and by controlled spreading of the two ends of the bow away from one another the miniature speakers are placed on the entries to the auditory canals. After this operation the user ascertains that the chin bow receiver has been automatically turned on. This on/off philosophy in addition preserves the battery charging and the preset loudness is maintained when the head set is put on again.
In similar existing products the receiver is switched by the user using a combined on/off switch and loudness controller. When turned off, the loudness controller is always turned to zero. In particular for users who are hard of hearing and for whom the device is especially well suited, after taking off the receiver it is often forgotten to be turned off. Upon re-use it is then ascertained that the battery energy is exhausted or the battery is dead, and the device is not longer immediately ready to operate. In addition, the user must again adjust the loudness appropriate to him each time it is turned on. These disadvantages are eliminated with the article of the invention.
A circuit in accordance with the invention in the chin bow receiver provides for automatic turn-off of the receiver to engage when the receiving quality falls below a certain quality tolerance boundary. This means that the wearer will always instinctively assume that receiving position which allows transfer based on the stipulated quality control. Accordingly if the chin bow receiver is located outside of the transmission area or the infrared beam is disrupted, the chin bow receiver turns off the disrupted audio transmission, but however instantaneously turns it on again as soon as the reception is again acceptable by the corresponding turning of the wearer in the direction of the transmitter. Thus the wearer is no longer burdened by undesirable and unpleasant audio distortions which essentially can greatly reduce the acceptance of the chin bow receiver.
The transmitted infrared rays are on only as long as a television program or music is being received. When the audio-emitting device is turned off, the transmitted infrared rays turn off after a few minutes.
With a well placed and easily operated switch in the transmitter which is not detailed, it is possible at any time to choose between mono or stereo audio transmission.
One embodiment of the invention is detailed below using the drawings. All features which are not important to the direct understanding of the invention have been omitted. The same features in the different figures are provided with the same reference numbers.